1. Field of the Invention
The invention relates to an endoscopic surgical instrument. More particularly, the invention relates to a flexible instrument for the transoral invagination and fundoplication of the stomach to the esophagus.
2. State of the Art
Gastroesophageal fundoplication is a procedure for the treatment of gastroesophageal reflux disease (GERD), a condition in which gastric acids are regurgitated into the esophagus resulting in esophagitis, intractable vomiting, asthma, and aspiration pneumonia. The fundoplication procedure involves wrapping the fundus of the stomach around the lower end of the esophagus and fastening it in place. Traditionally, this procedure is accomplished via open surgery with the use of sutures to secure the plicated fundus of the stomach around the esophagus without penetrating (incising) the stomach.
U.S. Pat. No. 5,403,326 to Harrison et al. discloses a method of performing endoscopic fundoplication using surgical staples or two-part surgical fasteners. The procedure disclosed by Harrison et al. involves performing two percutaneous endoscopic gastrotomies (incisions through the skin into the stomach) and the installation of two ports through which a stapler, an endoscope, and an esophageal manipulator (invagination device) are inserted. Under view of the endoscope, the esophageal manipulator is used to pull the interior of the esophagus into the stomach. When the esophagus is in position, with the fundus of the stomach plicated, the stapler is moved into position around the lower end of the esophagus and the plicated fundus is stapled to the esophagus. The process is repeated at different axial and rotary positions until the desired fundoplication is achieved. While, the procedure disclosed by Harrison et al. is a vast improvement over open surgery, it is still relatively invasive requiring two incisions through the stomach. Moreover, the procedure requires the manipulation of two different tools in order to position the fundus and to secure the fundus to the esophagus.
U.S. Pat. No. 5,571,116 to Bolanos et al. discloses a non-invasive treatment of gastroesophageal reflux disease which utilizes a remotely operable invagination device and a remotely operable surgical stapler, both of which are inserted transorally through the esophagus. According to the methods disclosed by Bolanos et al., the invagination device is inserted first and is used to clamp the gastroesophageal junction. The device is then moved distally, pulling the clamped gastroesophageal junction into the stomach, thereby invaginating the junction and involuting the surrounding fundic wall. The stapler is then inserted transorally and delivered to the invaginated junction where it is used to staple the fundic wall.
Bolanos et al. disclose several different invagination devices and several different staplers. Generally, each of the staplers disclosed by Bolanos et al. has an elongate body and a spring biased anvil which is rotatable approximately 15xc2x0 away from the body in order to locate the invaginated gastroesophageal junction between the body and the anvil. The body contains a staple cartridge holding a plurality of staples, and a staple firing knife. Each of the invagination devices disclosed by Bolanos et al. has a jaw member which is rotatable at least 45xc2x0 and in some cases more than 90xc2x0 to an open position for grasping the gastroesophageal junction. One of the chief disadvantages of the methods and apparatus disclosed by Bolanos et al. is that the stapler and the invagination device must be both be present in the esophagus at the same time. With some of the embodiments disclosed, the presence of both instruments is significantly challenged by the size of the esophagus. In all of the embodiments, the invagination device is always laterally spaced apart from the stapler. Thus, the stapler cannot staple the invaginated tissue, per se, but can only staple tissue which is laterally adjacent to the invaginated tissue. The relatively small rotational movement of the anvil of the stapler further complicates the accommodation of tissue adjacent to the invaginated tissue. In addition, surgical staples have some inherent disadvantages as compared to other fasteners. The relatively small surface area of surgical staples allows them to pass through tissue over time, thereby unfastening the tissue and allowing the staples to migrate to other parts of the body. Bolanos et al. appears to recognize this disadvantage and proposes the application of a bolster or pledger to the tissues prior to stapling. Bolanos et al. do not explain how this can be accomplished transorally using the apparatus disclosed. In addition, while Bolanos et al. make a broad reference to other types of fasteners, the substantial size constraints imposed on the apparatus which are delivered transorally would seem to prohibit any type of fastener other than the staples shown by Bolanos et al. The actuating mechanism of the device disclosed by Bolanos et al. is somewhat awkward. In particular, the stapler anvil is biased to the open position, and it is not clear whether or not the stapler anvil can be locked in a closed position without continuously holding down a lever. In addition, it appears that the staple firing trigger can be inadvertently operated before the anvil is in the closed position. This would result in inadvertent ejection of staples into the stomach or the esophagus of the patient.
It is therefore an object of the invention to provide an endoscopic surgical instrument for invagination and fundoplication of the stomach to the esophagus.
It is also an object of the invention to provide an endoscopic surgical instrument for invagination and fundoplication of the stomach to the esophagus which is minimally invasive.
It is another object of the invention to provide an endoscopic surgical instrument for invagination and fundoplication of the stomach to the esophagus utilizing fasteners which do not require bolsters or pledgers.
It is a further object of the invention to provide an endoscopic surgical instrument for invagination and fundoplication of the stomach to the esophagus which is delivered transorally to the surgical site.
It is an additional object of the invention to provide an endoscopic surgical instrument for invagination and fundoplication of the stomach to the esophagus which is capable of plicating tissue directly in line with invaginated tissue.
Yet another object of the invention is to provide an endoscopic surgical instrument for invagination and fundoplication of the stomach to the esophagus which is easy to use and which cannot be accidentally triggered.
In accord with these objects which will be discussed in detail below, the endoscopic surgical instrument of the present invention includes a torsionally rigid but flexible tube having a proximal end and a distal end, a grasping and fastening end effector coupled to the distal end of the tube, and a manual actuator coupled to the proximal end of the tube. The grasping and fastening end effector preferably includes a separate grasper and a separate fastener. The manual actuator is coupled to the grasper and fastener of the end effector by a plurality of flexible cables which extend through the flexible tube. The tube preferably contains a lumen for receiving a manipulable endoscope and the end effector preferably includes a passage for the distal end of the endoscope. The end effector has a store for a plurality of male fastener parts, a store for a plurality of female fastener parts, a rotatable fastener head for aligning a male fastener part and a female fastener part with tissues therebetween, a rotatable firing member for pressing a male fastener part through the tissues and into a female fastener part, and a rotatable grasper located between the fastener head and the firing member.
According to presently preferred embodiments, the overall diameters of the flexible tube and the end effector (when the fastener head is rotated to the open position and the grasper is rotated to the closed position) do not exceed approximately 20 mm (and preferably less than 16 mm) so that the instrument may be delivered transorally to the fundus of the stomach. The end effector preferably includes a substantially cylindrical stationary part which houses the store of male fastener parts and the firing member. Male fastener parts are ejected by the firing member through a substantially radial port in the substantially cylindrical stationary part of the end effector. The rotatable fastener head is hingedly coupled to a distal portion of the stationary part of the end effector and is rotatable from a first (open) position wherein the fastener head is rotated distally away from the stationary part to a second (closed) position wherein the fastener head is rotated proximally toward the stationary part. The store of female fastener parts is preferably contained within the fastener head and a female fastener shuttle on the fastener head moves a female fastener from the store into alignment with the substantially radial port when the fastener head is rotated to the closed position.
The presently preferred store for male fastener parts includes a longitudinal track arranged proximally of the rotatable firing member in which male fastener parts are arranged one behind the other. Male fastener parts are moved distally along the track by a first biasing member. According to one embodiment, the firing member includes a flange which blocks distal movement of male fastener parts while a male fastener part is being ejected. According to a presently preferred embodiment, a spring leaf with a pair of bent teeth engages the distal end of the next male fastener part in the track keeping it from moving off the track. When the firing member moves down to grab another male fastener part, the leaf is deflected allowing the next male fastener part to enter the firing member. The presently preferred store for female fastener parts includes an orthogonal chamber in which female fastener parts are stacked on top of each other and a second biasing member for moving the female fastener parts onto the female fastener shuttle. The presently preferred female fastener shuttle is a sliding tray which is located adjacent to the store of female fastener parts. The second biasing member pushes female fastener parts into the tray and the tray moves laterally away from the store of female fastener parts when the rotatable fastener head is moved from the open position to the closed position.
The rotatable fastener head, the firing member, and the grasper are preferably each controlled by an individual cable; and the proximal actuator includes three levers, each coupled to a respective cable, for individually operating the rotatable fastener head, the firing member, and the grasper. According to a presently preferred embodiment, the manual actuator includes a lock-out feature which prevents the inadvertent firing of male fastener members until the fastener head is rotated into the proper position. The manual actuator also includes a releasable lock for locking the grasper in the closed position.
According to one embodiment, the male fastener member is a circular disk with a central upstanding barbed projection and the female fastener member is a circular disk with a central hole engageable by the barbed projection of a male fastener member. According to another, presently preferred embodiment, the female fastener is rectangular with a central hole engageable by the barbed projection of a male fastener member. The female member is preferably provided with a plurality of weak peripheral extensions which allow the member to be held in the shuttle tray, but forcibly removed therefrom after it is coupled to a male member.
The apparatus of the invention is advantageously utilized in a fundoplication procedure. The instrument is prepared by inserting a manipulable endoscope into the proximal end of the instrument and threading the endoscope through the lumen of the flexible tube out through the end of the end effector. With the grasper closed and the rotatable fastener head in the first (open) position, the end effector is inserted into the mouth of the patient and guided down through the esophagus into the stomach with the aid of the endoscope. When the end effector is distal of the fundus (or lower esophageal sphincter), the grasper is opened and the end effector is raised toward the fundus so that the fundus and the lower end of the esophagus are located between the stationary part of the end effector and the grasper. The grasper is then closed to clamp together the tissue around the juncture of the esophagus and the fundus. With the grasper closed, the rotatable fastener head is closed, raising it up toward the fundus and lifting the fundus up against the esophagus. With the instrument in this configuration, the firing member is actuated and a male fastener member is ejected out of the radial port, through the esophagus and the fundus, and into a female fastener member which is held by the tray in the rotatable fastener head. The firing member is then returned to its initial position moving the flange or the leaf away from the male fastener store and allowing a second male fastener to be pushed onto the second rotatable member. The rotatable fastener head is moved to the open position, releasing the female fastener, and returning the tray to the store of female fasteners to receive a second female fastener. The grasper is opened and the instrument may then be repositioned and the above procedure repeated until the desired fundoplication is achieved.
Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.